Agricultural combines are large machines that harvest, thresh, separate and clean an agricultural crop. The resulting clean grain is stored in a grain tank located on the combine. The clean grain can then be transported from the grain tank to a truck, grain cart or other receiving bin by an unloading auger.
Rotary combines have one or two large rotors for threshing and separating the harvested crop material. In most rotary combines the rotor or rotors are arranged along the longitudinal axis of the machine. These rotors are provided with an infeed section for receiving harvested crop material, a threshing section for threshing the harvested crop material received from the infeed section and a separating section for freeing grain trapped in the threshed crop material received from the threshing section.
Rotors have been provided for combines in a variety of configurations to optimize harvesting efficiency for a wide variety of crops and crop conditions. Examples include variations on cylindrical and frusto-conical drum shapes disclosed in U.S. Pat. Nos. 4,139,013, 4,266,560, and 4,272,426.